A micro-electro-mechanical system (MEMS) is a technique that incorporates microelectronics and machines and is a critical component for sensing or function execution. MEMS is extensively applied in daily tools such as accelerators, detectors and actuators, and has been developed towards miniaturization during the recent years. For example, the U.S. Pat. No. 9,249,008, “MEMS Device with Multiple Electrodes and Fabricating Method thereof”, teaches a special arrangement of a first electrode, a second electrode and a third electrode, in a way that the MEMS device such as a differential pressure sensor, differential barometer, differential microphone and decoupling capacitor is facilitated to be miniaturized.
To effectively keep a heat source focused, a recess for accommodating air is usually designed in a common MEMS process. However, this recess reduces the strength of an overall device, and collapsing of an edge is easily caused during a subsequent cutting process, resulting in residuals or cleaning liquid likely accumulated during the cutting process, and hence a lowered yield rate and increased costs.
Further, to sense multiple types of gases, multiple MEMS sensors need to be installed by multiple repeated steps, which further increase production costs and prolong production time. Therefore, there is a need for a solution that resolves the above issues.